Steam-boiler and furnace



(No Model.)

J. E. MOORBARY. STEAM BOILER AND FURNACE.

No. 451,504. Patented May 5,1891.

III"

Z UNITED STATES PATENT OFFICE.

JONAS E. MCCREARY, OF CHICAGO, ILLINOIS.

STEAM-BOILER AND FURNACE.

SPECIFICATION forming part of Letters Patent No. 451,504, dated May 5, 1 891.

Application filed December 20, 1890. Serial No. 375,380. (No model.)

To all whom it may concern:

Be it known that I, JONAS E. MOCREARY, residing at Chicago, in the county of Cook and State of Illinois, and a citizen of the United States, have invented certain new and useful Improvements in Steam-Boilers and Furnaces, of which the following is a specification, reference being had to the accompanying drawings, in which- Figure 1 is a front elevation, a portion of the front of the boiler being broken away. Fig. 2 is a longitudinal vertical section of the forward part of my improved boiler and furnace. Fig. 3 is a detail, being a longitudinal vertical section of the smoke-conduit and a portion of the steam-inlet pipe; and Fig. 4 is a detail, being a horizontal section of a modification of the lower section of the smokeconduit.

Only such parts of a boiler and furnace are shown as are necessary to the illustration of my invention.

The common forms of smokepreventing steam-boilers-and furnaces make use of steam conducted from the boiler to cause a current of air to flow into the furnace in order to secure a more perfect combustion by the consumption of mixed air and steam, and thus prevent the original formation of smoke. To successfully-operate smoke-preventers made on this plan it has been found necessary to heat the air thus introduced into the furnace to a high temperature, both to secure more perfect mixture of the air and steam and to prevent condensation of the steam, and consequent corrosion of the boiler and loss of heat. The heating of the air and its intermixture with the steam have been found to be great obstacles to the successful operation of such devices and add greatly to their expense.

The objects of my invention are to avoid the above objections and to provide asmokepreventing attachment for steam-boilers and furnaces which will not require the introduction of fresh air into the comb ustion-chamber of the furnace except as it enters through the usual draft, but which will effectually purify the smoke before it leaves the boiler and furnace, and which will not interfere with the draft.

A further object of myinvention is to provide a smoke-pu rifyin g attachment for steamboilers and furnaces which will be inexpensive and which may be readily placed in position. trated in the drawings and as hereinafter described. That which I regard as new will be pointed out in the claims.

In the drawings, A indicates an ordinary boiler, having the usual forward compartment orsmoke-chamber a, through which the smoke passes on its way to the smoke-stack B.

C indicates a steam-pipe leading from the steam-dome to and extending across the front.

of the boiler, as best shown by the dotted lines in Fig. 1, which pipe C is secured to the front of the boiler and furnace in any suitable manner. The pipe C is provided at some convenient intermediate point with an ordinary'stop-valve D, by which the supply of steam may be easily regulated.

Extending up a short distance into the smoke-chamber a of the boiler, and leading from it to the combustion-chamber E of the furnace, are one or more smoke-conduits composed of sections F F, which are preferably united at rightangles, as shown in Fig. 8, and pass downward and backward through the supporting wall or inclosure of the boiler and open into the combustion-chamber E. The section F is preferably made to end flush with the inner face of the wall of the combustion-chamber E, but may extend a short distance into said chamber if a stronger draft is desired.

The sectionF is preferably made square at the top and has pivoted to it near one of its upper edges a drop orbutterfly valve J, which opens downward by slight pressure and is normally held in a closed position by the weight of a projecting arm or lever j.

Extending into the section F of each conduit and terminating slightly beyond the lower end of the section F, as best shown in Fig. 3, is a smaller steam-pipe 0, leading from the steam-pipe C. The pipe 0 is made smaller than the section F, so that a draft down the sectionFmay be created by the action of the steam in passing through said pipe 0, and also to permit of the passage of the smoke downward from section F through section E into the combustion-chamber E.

In the ordinary form of boiler having the I accomplish these objects as illussmokestack in the forward end the smoke passes through the smokechamber u, and thence upwardinto the smoke-stack. By the use of my improved boiler and furnace when the valve D is opened steam is admitted through pipes C and 0 into section F of the conduit, whence, the valve J being normally closed, the steam escapes into the comb ustionchamber E, causing a draft downward thro ugh sections F F into the combustionchamber, which draft opens the valve .T, and it is held open by the downward pressure created by the draft, By this means the unconsumed carbon and heavier gases are drawn by suction through the conduit F F, as indicated by the arrow, and into the combustion-chamber E of the furnace, where they are again subjected to an intense heat and produce a more nearly perfect combustion. They then pass through the tubes of the boiler again and out at the smoke-stack, being heated to a higher temperature and greatly purified. \Vith a properly-regulated steam-pressure in the pipes Cand c the draft down the conduit F F will not draw the lighter gases into the furnace again, as such gases will be in the upper part of the smoke-chamber a, and will not Come so readily within the influence of the draft, as the section F extends only a short distance into the compartment or smokechamber a.

It will be noted that when the smoke first comes from the furnace it is already at a high temperature, and therefore will not materially condense the steam, which also passes into the furnace. The tendency to corrode the boiler, which is common to most smoke-consuming boilers and furnaces using steam, is by this means avoided.

In order to better expose the unconsumed carbon and other impurities to the heat of the furnace, I preferably horizontally flatten the mouth of section F of the conduit, which causes a more general distribution of the impurities throughout the furnace. The mouth of section F may be rounded or bell-shaped. The inner end of the section F is subjected to intense heat, and therefore I provide this section with a detachable nozzle 1", which is flattened horizontally and expands towardits delivery-mouth, as in Fig. 4, for the purpose of spreading and distributing the unconsumed products of combustion over the fire in the fire-box. The inner end of the nozzle f is adapted to encircle the end of section F, as shown at f in Fig. l, and is interiorly flanged in order to make a more perfect connection. hen it is desired to remove the nozzlef, a portion of the brick-work of the wall which incloses the section F is removed, when the nozzle may be changed and the brick-work built up again.

I do not regard the use of steam as essential to the operation of my device, as any other blast may be used to create a downward draft through the conduit F F. The use of steam is preferable, however,owingto its convenience and to the fact that as it is already at a high temperature it will not red uee the temperature of the furnace appreciably.

\Vhat I claim as new, and desire to secure by Letters Patent, is-

1. In a boiler and furnace, the combination, with a smoke-conduit composed of sections F F, connecting the front of the boiler wit-l1 the combustion-chamber of the furnace, and a downwardly-opening overbalanced valve pivoted in the upper section thereof, of a steampipe adapted to conduct steam from said boiler into the section F of the smoke-conduit and terminating slightly forward of the section F of the smoke-conduit, substantially as and for the purpose specified.

2. The combination of the boiler A, smokechamber a, valve-capped tubes F, and horizontal tubes F with the steam-tube G, extending down and across in front, having branch pipes 0 extending into the tubes F, and the furnace-chamber E, substantially as and for the purpose specified.

JONAS E. MCCREARY.

\Vitnesses:

JOHN L. JACKSON, ALBERT II. ADAMS. 

